Zhang Wenchao, Wang Hongqiang, Zhang Na, Liu Huaguang, Chen Zhuo, Zhang Lijuan, Guo Shaopeng, Li Dan, Xu Jianzhong
Key Laboratory of Analytical Science and Technology of Hebei Province, College of Chemistry & Environmental Science , Hebei University , Baoding 071002 , China.
Institute for Superconducting & Electronic Materials , University of Wollongong , NSW 2522 , Australia.
ACS Appl Mater Interfaces. 2019 Aug 21;11(33):29807-29813. doi: 10.1021/acsami.9b07540. Epub 2019 Aug 8.
Alkali metal-sulfur/selenium batteries have attracted much attention because they offer promising high energy density. However, the shuttle effect of the polysulfide dissolutions, poor electrical conductivity, and relatively large volume variations greatly hinder their potential applications. Herein, a novel organic carbon/selenium sulfide (OC/SeS) composite has been prepared by a one-step in situ method by heating the mixture of commercial polyacrylonitrile (PAN) with selenium sulfide powder in vacuum. The carbonized PAN matrix with an N-doped carbon ring structure could effectively confine SeS in the form of small molecules and regulate its electronic structure. The superior sodium/potassium storage performance of the OC/SeS composite electrodes stems from their rational chemical structure design, including high electrical conductivity of the N-doped organic carbon network and chemical binding with SeS molecules. As a result, the OC/SeS cathode delivers a reversible capacity of 416 mAh g after 700 cycles for sodium-ion batteries and 216 mAh g after 500 cycles for potassium-ion batteries at 0.5 A g, respectively. These findings could open a new window to develop selenium sulfide cathode for metal-sulfur/selenium batteries.
碱金属硫/硒电池因其有望实现高能量密度而备受关注。然而，多硫化物溶解的穿梭效应、较差的导电性以及相对较大的体积变化极大地阻碍了它们的潜在应用。在此，通过在真空中加热商业聚丙烯腈（PAN）与硫化硒粉末的混合物，采用一步原位法制备了一种新型有机碳/硫化硒（OC/SeS）复合材料。具有氮掺杂碳环结构的碳化PAN基体能够有效地将SeS限制为小分子形式，并调节其电子结构。OC/SeS复合电极优异的钠/钾存储性能源于其合理的化学结构设计，包括氮掺杂有机碳网络的高导电性以及与SeS分子的化学结合。结果，OC/SeS阴极在0.5 A g的电流密度下，钠离子电池经过700次循环后可逆容量为416 mAh g，钾离子电池经过500次循环后可逆容量为216 mAh g。这些发现可为开发用于金属硫/硒电池的硫化硒阴极打开一扇新的窗口。
